Pivotal supporting devices particularly for mine roof supports



M41}! 396? P. D. DAWS-RATCLIFFE 3,309,054

PIVOTAL SUPPORTING DEVICES PARTICULARLY FOR MINE ROOF SUPPORTS Filed Aug. 2. 1965 3 Sheets$heet l w: E 77a 7A i & 4/62.

'l LLJ I INVENTORI March 1967 P. n. DAVIS-RATCLIFFE 3,309,054

PIVOTAL SUPPORTING DEVICES PARTICULARLY FOR MINE ROOF SUPPORTS Filed Aug. 2, 1965 3 Sheets-Sheet 2 INVENTORZ WW PAM/1 2222 fire arch 1967 P. D. DAVIS-RATCLIFFE 3,309,054

PIVOTAL SUPPORTING DEVICES PARTICULARLY FOR MINE ROOF SUPPORTS Filed Aug. 2, 1965 3 Sheets-Sheet INVENTOR:

United States Patent Qfitice sseaesi Patented Mar. 14, 1967 3,309,054 PIVOTAL SUPPORTING DEVICES PARTICULARLY FUR MINE ROOF. SUPPORTS Peter Derek Davis-Ratclifie, Penketh, Warrington, England, assiguor to Gullick Limited, Wigan, England, a British company Fiied Aug. 2, 1965, Ser. No. 476,333 Ciaims priority, application Great Britain, Aug. 11, 1%4, 32,595/64 11 Claims. (Cl. 248-354) This invention is for improvements in or relating to pivotal supporting devices for members which also require to be locked or held against pivoting movement.

The invention is particularly, although not exclusively concerned with hydraulic mine roof supports or chocks of the kind comprising a telescopic prop or props or legs adapted to be extended by hydraulic pressure-fluid. Such supports commonly comprise a base on which a plurality of props are mounted and a roof-bar structure supported on the upper parts of the props and which is applied to the roof when the props are extended. Provision is made whereby the props can be moved angularly out of the vertical. For instance, concave/ convex seatings may be provided between the upper and lower ends of the props and the roof-bar structure and base respectively. The support may also include a double-acting ram means which, when extended, serves to push a coal conveyor towards the coal face, as cutting of the coal proceeds, and when anchored to, say, the conveyor and retracted, serves to advance the support up towards the conveyor.

With hydraulic roof supports and particularly supports of the chock type as above described, it has been found in practice that there is a tendency, due to geological conditions, for the roof of a mine to move relatively to the floor after removal of the coal or mineral being obtained. This movement is usually compensated for or allowed to a limited extent by the provision of resilient mountings for the extendible roof-supporting members or props which as indicated above are permitted some angular movement. Such resilient mountings are commonly of rubber or like material and tend to deteriorate in service, and have other disadvantages.

One object of the'present invention is to provide an improved arrangement which will allow for relatively unrestricted movement of the support members or props, when set, to the extent necessary to provide for the above-mentioned relative movement between roof and floor and which, at the same time, when the support unit is being advanced and the props are released from between fioor and roof, will provide the necessary control over movement of the props.

According to the present invention there is provided a device comprising two pivotal supports for a member, at least one of said pivotal supports being movable with respect to the other so that they have a position in which their pivotal centres coincide, whereby said member is pivotally supported, and a position in which said centres are out of coincidence whereby the member is held against pivotal movement.

The member just referred to may be a mine roof supporting prop or one of several props incorporated in a mine roof supporting chock and'some or all of which are provided with a pivoting and locking arrangement as described.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings. In the drawings:

FIGURE 1 shows an application of the invention to a mine roof supporting prop, the prop being in the free to pivot condition and upright,

FIGURE 2 shows the arrangement according to FIG- U'RE l but with the prop slightly tilted or pivoted out of the vertical to allow for the above-mentioned tendency for the roof to move relatively to the floor.

FIGURE 3 shows an arrangement, similar to that illustrated in FIGURES l and 2 applied to a multiple leg chock, and

FIGURE 4 shows an embodiment of the invention applied to the advancing ram means of a hydraulic roof support or chock, the ram being in the free to pivot condition.

Referring first to the embodiment of the invention shown in FIGURES 1 and 2, the support has a base 10 on which is mounted a hydraulically extensible telescopic prop 11 which at its upper part supports the roof-bar structure or cap 12. Convex/concave seatings are provided where the roof-bar structure 12 rests on the upper ends of the props.

Generally (i.e., when the support is in the form of a chock) there will be two, three, four or more props mounted on the base it) or on two or more bases, which may be linked together.

The mounting on the base 10 for the prop 11 comprises a block or pad 13 having a concave face in which is seated the convex surface of the foot 14 of the prop.

The centre of curvature of these concave/convex faces acting hydraulic piston and cylinder device 17. Valves 17a are provided for controlling the operation of the device 17.

In the condition shown in FIGURE 1, which is the a condition when a support is set between floor and roof and is supporting the roof, the prop 11 is free to move angularly (i.e., pivot or rock) on the base pad 13, to allow for movement of the roof relative to the floor, because the centre of curvature of the spherical bush or sleeve 15 coincides with the centre of curvature C of the convex/concave faces of the pad 13 and foot 14. For instance, the prop can move to or be set in the angular position indicated in FIGURE 2.

When, however, the prop has been released from between floor and roof, e.g., when it is required to advance it up towards the conveyor and any freedom of movement of the prop would be a nuisance, then the arm 16 and spherical sleeve 15 are raised, by introducing pressure-fluid into the cylinder 17, to the position shown in dotted lines in FIGURE 2. In this position the centre of curvature of the spherical sleeve 15 is out of coincidence with the centre C and tilting movement of the prop cannot take place. When the support has been reset the ram 17 is operated so as to retract the arm 16 back to the position shown in full lines in FIGURES l and 2 so that the prop is again free to move.

The arrangement just described could, of course be used to lock a prop in an angularly set, roof supporting position should this be desirable. For such an arrangement the axis of the piston and cylinder device 17 will be parallel to said angular setting of the prop.

The support shown in FIGURE 3 is similar to that described in British patent specification No. 950,066 and in the specifications of USA. application for patent No. 89,159 and German application for patent No. G 31,545. The rear unit of the support has a plurality of props or legs 11 mounted on its base It) as above described with reference to FIGURES l and 2. The locking arrangement for the props or legs is also similar to that described with reference to FIGURES 1 and 2 except that a single hydraulic device 17 operates a double ended locking member 15, 16 for a pair of the legs or props 11.

3 Mounted in. the base 19 is a double acting ram 18 for pushing over the conveyor and advancing the support as previously described, the ram having a thrust bar 18a coupled to'the conveyor as indicated at 18b.

FIGURE 4 shows an application of the invention to the cylinder of a hydraulic or like ram (e.g., theadvancing ram 18 of a roof support as shown in FIGURE 3) where it is desirable that universal movement for the cylinder should be available whilst in certain circumstances the cylinder should be locked against such movement.

Inthe embodiment of the invention shown in FIGURE 4 the cylinder 125s, of the ram 18 (FIGURE 3) is carried by an annular yoke member 19* by which it is supported from a fixed mounting 20. This mounting could, for example be fixed to the base or" the support shown in FIGURE 3.' The yoke member 19 has an annular concave face 21 which seats on the convex face 22 of the mounting 2i).

Slidably mounted on the ram 18 is a spherical bushor sleeve 23, said bush being located in a convex seating in a member 24 slidably supported in the mounting 20;,

When the parts are in the relative positions shown in FIGURE4 in which the curvature of the concave/ convex faces 21 and 22 has the same centre C as the curvature of the spherical bush or sleeve 23, the ram 18 is permitted more or less universal movement. to fix the ram, i.e., prevent universal or other movement thereof, the member 24 together with the spherical sleeve 23 ismoved along the axis of the ram so as to create an eccentric or locked condition.

Instead of the bush or sleeve or 23 having a part spherical surface it may, for example, have a cylindrical surface where freedom of movement in one plane only is required.

I claim:

1. A device comprising two pivotal supports for a member, at least one of said pivotal supports being movable with respect to the other so that they have a positionin which their pivotal centres coincide, whereby .said

member is pivotally supported, and a position in which said centres are out of coincidence whereby the member. is held against pivotal movement.

2. A device comprising two pivotal supports for a member,v at least one of said pivotal supports having means slidably mounting it On said member for movement therea-long with respect to the other so that said pivotal supports have a position in which their pivotal centres coincide, whereby said member is pivotally supported, and a position in which said centres are out of coincidence whereby the member is held against pivotal movement.

3.-A device comprising two pivotal supports for a member, one of said pivotal supports including a foot for said member and a block on which said foot is mounted by a concave/convex mounting arrangement, the other pivotal support having means slidably mounting it on said member for movement .therealong with respect to the other pivotal support so that said pivotal supports have a position in which their pivotal centres coincide, whereby said member is pivotally supported and a position in which said centres are out of coincidence whereby the member is held against pivotal movement.

4. A device comprising two pivotal supports for a member, one of said pivotal supports including a foot for said member and a block on which said foot is mounted by a concave/convex mounting arrangement the. other When it is desired pivotal support including a bearing block and a sleeve which their pivotal centres coincide, whereby said mem-.

her is pivotally supported, and a position in which said centres are out of coincidence whereby the member is held against pivotal movement.

5. A device comprising two pivotal supports for a member,-at least one of said pivotal supports being movable with. respect to the other so that they have a position in which their pivotal centres coincide, whereby said member is pivotally supported, and apositionin which-said centres are out of coincidence 'whereby the member is held against pivotal movement, pressure-fluid ram means, and means operatively connecting said ram means to said movable pivotal support for effecting movement thereof.

6. A device as claimed in claim 4 wherein the means for moving the'bearing block and sleeve is a pressurefiuid-operated ram.

7. A mine roof support comprising .at least one pressure-fluid extensible prop member and two pivotal supports forsaid prop member spaced apart along the length thereof at least one of said pivotal supports being movable with respect to the other so that they have a position in which their pivotal centres coincide, whereby said prop member is pivotally'supported, and a position in which said centres are out of coincidence whereby the prop member is held against pivotal movement.

8. A mine roof support as claimed in claim 7 and further comprising a pressure-fluid-operated ram means for eifecting movement of said one pivotal support with respect to the other.

9. A mine roof support comprising atleast onevpressure-fluid extensible prop member, two pivotal supports for said prop member, one of said pivotal supports including afoot for said prop member and a block on which said foot is mounted by a concave/convex mounting arrangement, the other pivotal support including a bearing block and a sleeve having a concave/convex seating in said bearing block and slidably located on said prop member, pressure-fiuid-operated ram means and means operatively connecting said ram means to-said block for elfecting said movement of the block and sleeve along the.

prop member, so that the pivotalsupports have a position in which their pivotal centres coincide, whereby: said prop member is pivotally supported, and a positionin which said centres are out of coincidence whereby the prop member is held against pivotal movement.

10.- A pressure-fluid-operated ramzhaving two pivotal supp01'tS,at least one of said pivotal supports. being movable with respect to theother, along the lengthof the ram, so that they have a position in which their pivotal centres coincide, whereby said ram is pivotally supported, and a position in which said centres are out of coincidence whereby the ram is held against pivotal move-' ment.

11. A ram as claimed in claim 10 and further comprising a pressure-fluid-operated rarnrneans for effecting movement of said one pivotal support with respect to the other.

No references cited.

CLAUDE A. LE RoY, Primary Examiner.

F. DOMOTOR, Examiner. 

7. A MINE ROOF SUPPORT COMPRISING AT LEAST ONE PRESSURE-FLUID EXTENSIBLE PROP MEMBER AND TWO PIVOTAL SUPPORTS FOR SAID PROP MEMBER SPACED APART ALONG THE LENGTH THEREOF, AT LEAST ONE OF SAID PIVOTAL SUPPORTS BEING MOVABLE WITH RESPECT TO THE OTHER SO THAT THEY HAVE A POSITION IN WHICH THEIR PIVOTAL CENTRES COINCIDE, WHEREBY SAID 